<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>加法计算器</title>
    <style>
        body {
            background-color: violet;
        }
        input {
            border-color: white;
            border-radius: 50px;
        }
        * {
            text-align: center;
            padding: 20px;
            font-weight: 600;
        }
    </style>
</head>
<body>
<h1>加法计算器</h1>
<form action="/sum">
    <div>数字1:<input type="text" placeholder="请输入加数" name="add1"></div>
    <div>数字2:<input type="text" placeholder="请输入加数" name="add2"></div>
    <div><input type="submit" name="submit"></div>
</form>
</body>
</html>